The present invention is directed to calculators and more particularly to a hand held calculator which in addition to performing the conventional arithmetical calculations also performs conversions particularly directed to converting given units of measurements into different selected units of measurements and converting the serving quantities of recipes into different serving quantities and/or converting given recipe portion sizes to selected different portion sizes. All of the recipe conversions being directly related to the original converted recipe so as to maintain the same expected culinary result in the conversion.
The prior art includes at least the following U.S. Pat. Nos. 4,100,602; 4,244,020; 4,290,113; 4,321,674; 4,092,523 and 4,405,991.
U.S. Pat. No. 4,100,602 which is now assigned to the inventor of the present invention. In this patented invention, .recipe conversions are performed in a different manner. In this patent the calculation operation converts input data and required output data into a ratio and uses that ratio to perform each of the final calculations. There is no means provided for changing the serving quantity of a given recipe to a different serving quantity while altering the portion size of that given recipe to a different portion size simultaneously. Additionally, the referenced calculator does not have available an expanded number of different units of measure.
U.S. Pat. Nos. 4,224,020 and 4,321,674 relate to calorie conversions and accumulation devices which further accumulate calories as one of the three units which are limited to carbohydrates, protein and fat.
U.S. Pat. No. 4,405,991 is dedicated only to cooking times for food type, amount of food and desired results.
U.S. Pat. Nos. 4,092,523 and 4,290,113 are conversion calculators. In U.S. Pat. No. 4,092,523 conversions may be made from one type of unit to many other types of units through a conversion ratio for each conversion pair. The example used for this calculator is monetary conversions as between monies of different countries. This calculator includes memory stored conversion factors. Chained conversion are not performed. Individual conversion factors are used for each conversion operation. In U.S. Pat. No. 4,290,113 only two systems of conversion units are available.
The present invention provides an advancement of the state of the art in small calculators by providing a more accurate and user friendly dedicated multi-function calculator for use in recipe conversions.